Technote Details :: Update record primary key issue
Issue
I've created a page that allows updating records in a database, but when I preview it in the browser and try to submit information, I get an error message saying "tNG_update.prepareSQL:No Primary Key Column was set. (UPD_NO_PK_SET)".

Reason
This happens because the update page was accessed without sending a value for the Primary Key. Usually, update pages take the ID of the record to update from an URL parameter. If it is missing, the update operation cannot work properly, because there is no definite record.
Solution
When accessing an update page, make sure you always pass it a correct value for the primary key column of the table that's being updated. This is done easy, if the update page is called from a link that automatically passes the ID of the record to edit.